Diesel type engine



March 13, 1934.

DIESEL TYPE ENGINE Filed June 28, 1929 2 Sheets-Sheei; i?

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, 3e a i i@ (1i 6 la M zd il INVENTOR. 1@ H M005 2 @Y Ffa 6 ATTORNEY Patented Mari i3, 193

lididdlii 'ith ich@ htalph ill), lha/coe, dan liiiego, @iT/allaia Ailipplication inne 2th i929, derlei lilo., difatti@ (ci iraeti it @latina lily invention relates to two-cycle engines, more particularlyto two-cycle engines or the Diesel or mixed-cycle type, and the ohjects ,oi my invention are: First, to provide an internal s combustion engine or this class which may he built extremely light lor the power it develops, thereby iacilitating its use as an aircraft engine or for other vehicle engines where lightness is essential; second, to provide an internal comio bustion engine oi this class which is capable or running emciently at high speed, thereby enabling the engine to be compact tor itsv power output; third, to provide an internal combustion engine ci? the two-cycle type in which the erit; haust ports are caused to open and close inv advance or the intalre ports, therehy greatly reducing the fuel mixture or scavaging air losses common to the conventional two-cycle engine; iourth, to provide an internal combustion engine go oi the Diesel type in which double ignition and double comhustion takes place, the ilrst ignition and combustion being used principally to speed the second ignition and rate oi combustion tollowing therefrom; hith, to provide an internal g5 combustion engine oi the Diesel type in which partial combustion ol a rich iuel mixtureA oracles the incl and raises the temperature oi said :hiel in order that when said fuel is hrought in contact with air in a combustion chamber :io combustion is greatly facilitated; sinth, to provide an internal combustion engine oi the liiesei type in which the time oi combustion is soI re duced that although the engine is running at high speed, combustion need start only a iew as degrees before top center and yet efficiently utilize the latent energy oi the luci rifiniture; seventh, to provide an internal combustion en-n gine ci the Diesel type in. which the detonation and pre-ignition edects common to high-speed gg liiesel engines are localized and reduced to a miiuni so as to greatly reduce the weight and strength oi material :tormerly necessary to withstand the excessive pressure resulting trom said detonation and pre-ignition ettects; gg eighth, to provide an internal combustion en-1 gine oi this class which combines the ehicient scavaging of a tour-cycle engine with the simplicity oi? a two-cycle engine; and ninth, to provide on a whole a novelly constructed Diesel en gg, gine ol this class which is extremely sirnple ol construction proportional to its functions, duraw ble, efficient in its action and which will not readily deteriorate or get out oi order.

With these and other objects in view as will 55 appear hereinafter, my invention consists for certain novel features oi construction, combination 'and arrangement oi parts and portions as will be hereinafter described in detail and particularly set forth in the appended claims, reference being had to the accompanying drawtiti ings and to the characters oi reference thereon which form a part of this application, in wch:

Figure l is a fragmentary transverse sectional view oi. a power unit or an engine embodying my invention; lig. 2 is a plan view of the minor piston; l'ig. 3 is a sectional view oi'said piston through 3-3 ol liig. l; higs. l and 5 are diagrammaticai views oi my engine, illustrating the operation thereof; Fig. d is another diagrammatcal view thereof showing the relationship oi the pistons to the crankshaft; lilgu 'l is a reduced sectional view through 7-7 oi Fig. l with the pistons and injector removed; hig. d is a reduced transverse sectional view thereot through od or Fig. l, with the minor piston removed; lig. 9 is another transverse sectional view through 9--9 oi Fig. l, with the pistons removed; lo is a fragmentary sectional view similar to Fig. l oi a slight modidcatioh embodying my invention; and Fig. il is a plan view ot the minor piston which constitutes part oi .saidmodification.

Major cylinder i, minor cylinder 2, cylinder head 3, :minor piston et, injector il, maior piston o, crankshaft i, connecting rods d ande, cranica ld and il, modided minor piston la, and modim ned/iiniector i3, constitutethe principal and portions or my internal combustion engine.

.d maior cylinder l and a minor cylinder t are provided, 'which entend in the samefdirection pp parallel with each other and connect at their one adjacent end to a common cylinder head 3, which is preferably integral therewith.

@ver the minor cylinder 2, the cylinder head ii iorrns an eiitension thereoi'. "lhe upper portion ot said errtension terminates in a super-com:n pression chamber 3d. Between the super-cornIl pression chamber 3a and the junction hetween the cylinder and the cylinder head; said cylinder head 3 isprovided with a plurality oi ports ab which intersect the extension oi the minor cylinder 2.- e several ports 3h are separated one troni another byl webs Etc, the inner suriaoes oi which i'orin guides tor a minor piston ti adapt ed to reciprocate in the minor cylinder 2 and the extension thereoi iormed inthe head The head oi the super-compression chamber 3a is substantially nat and is4 provided with opening therethrough in which is mounted a fuel injector t, which is adapted to spray iuel im lili itil) dit ldd

lilith downwardly into the said super-compression chamber. A ring or combustion chamber 3d is formed in the cylinder head"3. The ring chamber 3d includes two spaces 3e in the form of arms which extend around the outside `of the extension of. the minor cylinder 2 and communicate with said cylinder and with said supercompression chamber through the ports 3b.

The lower margins of the arm-like spaces 3e are substantially flush with the lower margins of the ports 3b. The upper margins of the extended ends of these spaces 3e,that is the ends most removed from the major cylinder 1, are substantially flush with the upper margins of the ports 3b. These spaces 3e increase in height towards the major cylinder 1 and main portion of the firing chamber 3d. The arm-like spaces 3e join each other adjacent and above the side of the major cylinder next to the minor cylinder 2, and form the main portion of the ring or combustion chamber 3d. Thus, the sidewalls of the super-compression chamber or ignition chamberl 3a. extend into the firing chamber.

The portion of the head 3 over the major cylinder l forms an extension 3f thereof, but said extension is not as high as the one formed over the minor cylinder 2. -The r'ing chamber 3d includes this extension of the major cylinder 1. The major portion of the head of this extionsion 3f is relatively flat and the under surface thereof facing the major cylinder may be brought down as low as the under side of the upper margins of the ports 3b, as shown in Fig. l. 'Ihe portion of the head covering the major cylinder l adjacent to the main portion of the ring 'chamber 3d curves lupwardly rather abruptly and joins said main portion of the ring chamber, as shown best in Fig. 1.

A major piston 6 is adapted to reciprocate in the major cylinder l. The position of the piston at top center is such that very little clearance is left between the top of the piston and the flat portion of the extension 3f forming the larger part ofthe major cylinder head, as shown in Fig. l.

Positioned in the side walls of the major cylinder 1 is a plurality of intake ports la spaced apart one from another by webs 1b which form guides for conducting the piston past said ports. The piston is made long enough so that the skirt thereof always covers the ports la: when the head'of the cylinder is above said ports in order to prevent air from passing through said ports into the crankcase of the engine.

Similarly, a plurality of exhaust ports 2a are formed in the side walls of the minor piston 2. These ports are separated by a plurality of webs 2b which guide the minor piston 4 past the said port. Said minor piston is made long enough so that the exhaust ports are always covered, while th head of said piston is above said port in order hat the back pressure which may exist in the exhaust manifold connected with the exhaust ports will not enter the crank case.

The minor piston 4 is joined to a `crankshaft 7, through a connecting rod 8 and a crank 10. Similarly, the major piston 6 is joined to the crankshaft '7 by a connecting rod 9 and crank 1l, asy shown in Fig. 6. As indicated by the center lines drawn in Fig. 6, the axis of the major piston is set to one side of the/Wo crankshaft axis so that better leverage is obtained on the power stroke and also to provide a certain lag of the major piston relative to `the minor piston. Further lag is obtained by advancing the position of the crank 10 connected to the minor piston in ahead of the crank 11 connected to the major piston. This is done so that the minor piston both covers and uncovers the exhaust ports in advance of the covering and uncovering of the intake ports.

During the down stroke, due to the` lead ofthe minor piston, the relative positions of the two pistons are approximately that indicated by the dotted lines labelled A1 and A2 in Fig. 1. This dotted position shows the exhaust ports well open and the intake ports still closed. In the upward movement or compression stroke of the pistons, the relative positions are indicated by the dotted lines B1 and B2, in Fig. 1. From these, it can be seen that during the compression stroke the difference in levels of the heads of the two pistons is somewhat greater than the dierence in levels during the power stroke. Thus, it is possible to arrange the intake ports and exhaust ports so that the exhaust ports will be closed in advance of the intake ports and thereby economize the scavaging air as Well as enabling higher compression at the beginning of rthe compression stroke.

A diametrically extending web 4c joins the side walls and the under side of the top or head portion of the minor piston. The upper surface of the head 4a of the minor piston is made concave and has Acentered therein a substantially semi-spherical depression 4b. A passage 4d is provided in the bottom of the depression db. This passage extends downwardly into the web 4c and towards one side of the minor piston. The bottom of the passage 4d is enlarged, forming a small chamber 4e. An orifice 4f, forming an injector nozzle communicates with. the chamber 4e and pierces the side wall of the minor piston facing the main portion of the ring chamber 3d. Said injector nozzle extends upwardly from said chamber 4d. The position of the injector nozzle 4f is such that it is closed by the side walls of the minor' cylinder 2 until the top of the piston has almost reached the head of the supercompression chamber 3a, at which position the injector 4f raises above the `lower margin of the ports 3b so as to direct the fluids that may pass through the passage 4d and chamber 4e upwardly into the firing chamber 3d.

The operation of my engine is as follows:

Every upstroke of the major and minor pistons, causes air previously drawn in through the intakeI ports la to be compressed yi'n the firing chamber 3d and in the super-compression chamber 3a, which forms a part of said firing chamber until the minor piston 4 has passed the upper margins of the ports 3b. By the time the minor piston enters the super-compression chamber 3a and separates it from the firing chamber, the air trapped in said super-compression chamber is already under considerable pressure. When the minor piston has reached about `the position labelled C in Fig. l, fuel is injected through the injector 5. The fuel is injected in excess of the amount capable of being used by the minor piston and the supercompression chamber. The excess fuel collects on top of the piston in the depression 4b and along the passage 4d, and in the small chamer 4e. When the compression within the super-compression chamber has reached a. sumcient point, combustion takes place, further movement of the piston further compresses the fuel mixture until the nozzle or injector ify has lib dll

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passed the lower margin of one of the ports 3b and the fuel mixture has a chance to escape into the ring chamber 3d.

Due to the excess fuel in the super-compres sion chamber, only partial combustion taires place. This causes a cracking of the excess fuel and renders it in a more fit condition for complete and rapid combustion when brought in contact with air in the firing chamber 3d. Thus the super-compression chamber also functions as a fuel preparing chamber, and a partial combustion chamber.

The burning fuel mixture, together with the i ercess fuel not .burned by reason of the insufflcient air, is blown'out the nozzle if at high velocity, with great force, and in a very hot condition. The previously unburned fuel which has been prepared for proper combustion by the action of the super-compression chamber, when it comes in Contact with the air in the firing chamber 3d, immediately commences to burn. Due to the force of this as it is shot out, it is rapidly dispersed throughout the compression chamber, and complete mixture takes place practically instantaneously, so that combusiton taires place in practically all portions of the ring chamber at about the same time, thereby reducing the period of combustion to an interval of short duration, a duration short enough to enable the, engine to Vrun at a speed comparable with the Otto-cycle engine used .in vehicles.

Due to the relatively low pressure in the combustion chamber 3d, before combustion begins and due to the time of combustion being almost at top center, detonation and pre-ignition effect is reduced to a minimum. As shown in the drawings, the minor 'cylinder and piston are made relatively small so that what detonation and pre-ignition eect that occurs in the superccmpression cylinder is confined to a small `area and therefore, the deleterious effect thereof for.

Centered on the head of the minor piston 'if of the inodided structure, is an annular ridge im. "ffhe annular ridge lau forms at its ,inner side a well orsoclret 12b; said socket lZb pre ferably entends below the normal upper surface of the minor `pisinn l2, as shown in Fig. le. The base of the ridge ltd is pierced transversely by a plurality of small holes l2c which inter sect the side walls of the well orsoclret 12b, substantially tangential thereto. d diametrically disposed web 12d entends between op posite side walls of the piston and across the under side ci the head of thepiston l2, as shown in ffig. lb. it. passage ille extends downwardly from the well 12b and forms at its lower end a small chamber 121i. .il nozzle or injector' orce iig communicates between the chamber idf andthe side wallof the pistony l2 adjacent or orifice i2g are similar in construction to the corresponding portions of the first described minor piston Li.

A depression 3g is formed Ain the head of the super-compression chamber 3a. The side walls of said depression conform substantially to the outer-side walls of the ridge 12a, as shown in. Fig. l0. .An injector 13 is mounted in the depression 3g and is designed to extend part way into the well or socket 12b.

The operation Aof the modified structure isv similar to that of the nrst described structure. Air is compressed into the ring chamber 3d and super-compression chamber 3a by the action of both the major and minor pistons until said minor piston passes above the upper inargins of the ports-3b trapping a portion of the air in the super-compression chamber 3c.

Fuel is injected into the compression chamber from the injector 13 just 'after the said minor piston 12 has closed the ports 3b. The piston at the beginning of the injection is approximately at the position shown by the dotted lines labelled D in Fig. l0. As in the first described structure, more fuel is injected than can be utilized bythe air within the Supercompression chamber.

The excess fuel tends to collect on the upper fr t surface of the `piston and. in the well 12b. lgni- Y tion takes place soon after injection. The piston continues to move upwardly against the burning fuel mixture creating a high temperature and pressure. As in the first described structure, only partial combustion takes place in the super-compression chamber, due to the presence of excess fuel. This partial combustion prepares the excess vfuel for rapid and complete comm bustion when it comes in contact with the air in the firing chamber 3d. The fuel mixture and prepared excess fuel is released into the bring chamber at the proper time by the nozzle regis-y tering with one of the ports 3b.

The holes 12e create a twirling, turbulent motion of the air within the well 12b, during the compression and combustion within the super compression chamber. ll/fost of the air in the super-compression chamber, however, passes be tween the outside of the ridge 12a and the walls of the depression 3c and enters the well lib at the upper side thereof and in substantially the same direction as the fuel which is being in-n jected, asindicatcd by the arrows in lb. This facilitates proper mixture of the and fuel. .I

Though l2 have shown and described a partic= ular construction, combination and arrangement of parts and portions, and a certain modilisation thereof, l do not wish to be limited to this particular construction, combination and arrangement, nor to the modification, but desire to include in the scope of my invention the construction, combination and arrangement substantially as set forth in the appended claims.

Having thus described my invention, what f claim as new and desire to secure by letters Patent is: l

1. 1n an internal combustion engine, a major cylinder, a maior piston, a minor cylinder acljacent said maior cylinder-a passage connecting said cylinders, a minor piston, a reduced antlic maior Piston The Orifice 129' i8' S0 dl\\nular portion on the upper end of said minor ranged that nuids issuing therefrom are directed upwardly towards the main portion 3d of the firing chamber. Thus, it will be seen that the web 12b, passage 12e, chamber 12f. and nozzle piston forming a fuel receiving cup, a conformlng socket in the head end oi' said minor cylinder adapted to receive said annular portion, while said minor piston is in its compressing position,

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a. fuel injector extending through said head end Le: v

2. An internal combustion engine as climed into said socket, a, channel extending from within claim 1 in which lthe Wall ofrseid annular in said annular portion and terminating in an portion is pierced by substantially radial holes orice in the side Wall of said minor piston and for allowing passage oi gas intov said cup for 5 adapted to communicate with said connecting agitating the fuel therein.

passage when said minor piston occupies a fully compressing position.

RALPH D. LACOE. 

